Hi there, @HPTT. I am happy to share some details about the number of products you can add to your QuickBooks subscription. 

You will be happy to know that there's no storage limit for products you'd want to add, attachments, and other selected data. With that said, it's unlimited storage. However, a large number of items may lead to performance issues. 

In addition, I've got you this article in case you'd track a product or service in your QBO account: Set up and track your inventory in QuickBooks Online.

You may want to run a report to view helpful information on things and the status of your inventory. This article will help show you which reports are running depending on what kind of info you want to see: Use reports to see your sales and inventory status. 

Let me know if you need further assistance managing your inventory in QuickBooks. You can also click the REPLY button below if you have any additional QuickBooks-related concerns. I'll be more than happy to help you out again. Take care!